Possibilities and Limitations of Kinetic Studies in pls. insert line break here On-Surface Synthesis by pls. insert 2nd linebreak here Real Time X-ray Photoelectron Spectroscopy
Chemphyschem. 2024 Mar 25:e202400156. doi: 10.1002/cphc.202400156. Online ahead of print.ABSTRACTThe kinetics of coupling reactions on surfaces can be quantitatively studied in real time by X-ray Photoelectron Spectroscopy (XPS). From fitting experimental data, kinetic reaction parameters such as the rate constant's pre-exponential and activation energy can be deduced and compared to quantum chemical simulations. To elucidate the possibilities and limitations of this approach, we propose studies in which experimental data are first simulated and subsequently fitted. Knowing the exact kinetic parameters used in the simulati...
Source: Chemphyschem - March 26, 2024 Category: Chemistry Authors: Markus Lackinger Source Type: research

Pressure Induces Six-fold Coordination for the Lighter Pnictides Phosphorus and Arsenic Triiodide
In this study, we employ an evolutionary algorithm in conjunction with first-principles density functional theory (DFT) calculations to comprehensively investigate the structural transitions, electronic properties, and chemical bonding behaviors of XI3 compounds, where X denotes phosphorus (P) and arsenic (As), across a range of elevated pressures. Our computational analyses reveal a distinctive phenomenon occurring under compression, wherein the initially trigonal structures of PI3 (P 63) and AsI3 (R-3) undergo an intriguing transformation, leading to the emergence of six-coordinated monoclinic phases (C2/m) at 6 GPa and ...
Source: Chemphyschem - March 26, 2024 Category: Chemistry Authors: Pranab Gain Soumya Mondal Ayan Datta Source Type: research

Coarsening of quasi two-dimensional emulsions formed by islands in free-standing smectic films
Chemphyschem. 2024 Mar 26:e202400166. doi: 10.1002/cphc.202400166. Online ahead of print.ABSTRACTWe study the coarsening behavior of assemblies of islands on smectic A freely suspended films in ISS microgravity experiments. The islands can be regarded as liquid inclusions in a two-dimensional fluid in analogy to liquid droplets of the discontinuous phase of an emulsion. The coarsening is effectuated by two processes, predominantly by island coalescence, but to some extend also by Ostwald ripening, whereby large islands grow at the expense of surrounding smaller ones. A peculiarity of this system is that the continuous and ...
Source: Chemphyschem - March 26, 2024 Category: Chemistry Authors: Christoph Klopp Torsten Trittel Ralf Stannarius Source Type: research

New Perspectives on Delocalization Pathways in Aromatic Molecular Chameleons
This study comprehensively analyzes the magnetically induced current density of polycyclic compounds labeled as "aromatic chameleons" since they can arrange their π-electrons to exhibit aromaticity in both the ground and the lowest triplet state. These compounds comprise benzenoid moieties fused to a central skeleton with 4n π-electrons and traditional magnetic descriptors are biased due to the superposition of local magnetic responses. In the S0 state, our analysis reveals that the molecular constituent fragments preserve their (anti)aromatic features in agreement with two types of resonant structures: one associated wi...
Source: Chemphyschem - March 26, 2024 Category: Chemistry Authors: Luis Leyva-Parra Irene Casademont-Reig Ricardo Pino-Rios Lina Ruiz Mercedes Alonso William Tiznado Source Type: research

Doping effects on ethane/ethylene dehydrogenation catalyzed by Pt2X nanoclusters
Chemphyschem. 2024 Mar 25:e202400095. doi: 10.1002/cphc.202400095. Online ahead of print.ABSTRACTThe catalytic dehydrogenation of light alkanes is key to transform low-cost hydrocarbons to high value-added chemicals. Although Pt is extremely efficient at catalyzing this reaction, it suffers from coke formation that deactivates the catalyst. Dopants such as Sn are widely used to increase the stability and lifetime of Pt. In this work, the dehydrogenation reaction of ethane catalyzed by Pt3 and Pt2X (X = Si, Ge, Sn, P and Al) nanocatalysts has been studied computationaly by means of density functional calculations. Our resul...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Andoni Ugartemendia Jos é M Mercero Elisa Jimenez-Izal Abel de Cozar Source Type: research

XPS Analysis of FexNiyPS3  vdW Materials Used in the Hydrogen Evolution Processes
Chemphyschem. 2024 Mar 25:e202400039. doi: 10.1002/cphc.202400039. Online ahead of print.ABSTRACTIn response to the global demand for sustainable energy solutions, the quest for stable and cost-effective hydrogen production has garnered significant attention in recent decades. Here, the emergence of layered metal phosphorus trichalcogenides (MPX3, M: transition metal, X: chalcogen) materials with customizable composition and electronic structure holds great promise for such purposes. In the present study, we successfully synthesized large-scale and high-quality Fex$NyPS3. Subsequent systematic investigations were conducted...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Yefei Guo Guopu Cai Junhao Zhou Jiali Yang Elena Voloshina Yuriy Dedkov Source Type: research

Global Potential Energy Surfaces by Compressed-State Multistate Pair-Density Functional Theory for Hyperthermal Collisions in the O2 + O2 System
Chemphyschem. 2024 Mar 25:e202400078. doi: 10.1002/cphc.202400078. Online ahead of print.ABSTRACTInteractions between oxygen molecules play an important role in atmospheric chemistry and hypersonic flow chemistry in atmospheric entries. Recently, high-quality ab initio potential energy surface (PES) of the quintet O4 was reported by Paukku et al. [J. Chem. Phys. 147, 034301 (2017)]. 10543 configurations were sampled and calculated at the level of MS-CASPT2/maug-cc-pVTZ with scaled external correlation. The PES was fitted to a many-body (MB) form with the many-body part described by the permutationally invariant polynomial ...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Jie Jiang Jiawei Yang Qizhen Hong Quanhua Sun Jun Li Source Type: research

Unveiling the Cleavage Mechanism of an RNA Model Compound on the whole pH Scale: Computations Meet Experiments in the Determination of Reaction Rates
This study turns out to quantitatively reproduce the experimental data with accuracy and, in addition, provides useful mechanistic insight into the transesterification process of the investigated compound. The study indicates that the cleavage can occur through an ANDN, an AN+DN, and a DNAN mechanism depending on the pH values.PMID:38526551 | DOI:10.1002/cphc.202300873 (Source: Chemphyschem)
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Alessandro Nicola Nardi Alessio Olivieri Marco D'Abramo Riccardo Salvio Source Type: research

Tetrel Bonding of the Carbenium Ion Forms a Pentacoordinate Carbon Atom
Chemphyschem. 2024 Mar 25:e202400240. doi: 10.1002/cphc.202400240. Online ahead of print.ABSTRACTAs a flat trigonal species, the CR3+ carbenium ion contains a pair of deep π-holes above and below its molecular plane. In the case of CH3+ a first base will form a covalent bond with the central C, making the combined species tetrahedral. Approach of a second base to the opposite side results in a longer but rather strong noncovalent tetrel bond (TB). While the CMe3+ can also form a similar asymmetric complex with a pair of bases, it also has the capacity to form a pair of nearly equivalent TBs, such that the resulting symmet...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Steve Scheiner Source Type: research

Doping effects on ethane/ethylene dehydrogenation catalyzed by Pt2X nanoclusters
Chemphyschem. 2024 Mar 25:e202400095. doi: 10.1002/cphc.202400095. Online ahead of print.ABSTRACTThe catalytic dehydrogenation of light alkanes is key to transform low-cost hydrocarbons to high value-added chemicals. Although Pt is extremely efficient at catalyzing this reaction, it suffers from coke formation that deactivates the catalyst. Dopants such as Sn are widely used to increase the stability and lifetime of Pt. In this work, the dehydrogenation reaction of ethane catalyzed by Pt3 and Pt2X (X = Si, Ge, Sn, P and Al) nanocatalysts has been studied computationaly by means of density functional calculations. Our resul...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Andoni Ugartemendia Jos é M Mercero Elisa Jimenez-Izal Abel de Cozar Source Type: research

XPS Analysis of FexNiyPS3  vdW Materials Used in the Hydrogen Evolution Processes
Chemphyschem. 2024 Mar 25:e202400039. doi: 10.1002/cphc.202400039. Online ahead of print.ABSTRACTIn response to the global demand for sustainable energy solutions, the quest for stable and cost-effective hydrogen production has garnered significant attention in recent decades. Here, the emergence of layered metal phosphorus trichalcogenides (MPX3, M: transition metal, X: chalcogen) materials with customizable composition and electronic structure holds great promise for such purposes. In the present study, we successfully synthesized large-scale and high-quality Fex$NyPS3. Subsequent systematic investigations were conducted...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Yefei Guo Guopu Cai Junhao Zhou Jiali Yang Elena Voloshina Yuriy Dedkov Source Type: research

Global Potential Energy Surfaces by Compressed-State Multistate Pair-Density Functional Theory for Hyperthermal Collisions in the O2 + O2 System
Chemphyschem. 2024 Mar 25:e202400078. doi: 10.1002/cphc.202400078. Online ahead of print.ABSTRACTInteractions between oxygen molecules play an important role in atmospheric chemistry and hypersonic flow chemistry in atmospheric entries. Recently, high-quality ab initio potential energy surface (PES) of the quintet O4 was reported by Paukku et al. [J. Chem. Phys. 147, 034301 (2017)]. 10543 configurations were sampled and calculated at the level of MS-CASPT2/maug-cc-pVTZ with scaled external correlation. The PES was fitted to a many-body (MB) form with the many-body part described by the permutationally invariant polynomial ...
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Jie Jiang Jiawei Yang Qizhen Hong Quanhua Sun Jun Li Source Type: research

Unveiling the Cleavage Mechanism of an RNA Model Compound on the whole pH Scale: Computations Meet Experiments in the Determination of Reaction Rates
This study turns out to quantitatively reproduce the experimental data with accuracy and, in addition, provides useful mechanistic insight into the transesterification process of the investigated compound. The study indicates that the cleavage can occur through an ANDN, an AN+DN, and a DNAN mechanism depending on the pH values.PMID:38526551 | DOI:10.1002/cphc.202300873 (Source: Chemphyschem)
Source: Chemphyschem - March 25, 2024 Category: Chemistry Authors: Alessandro Nicola Nardi Alessio Olivieri Marco D'Abramo Riccardo Salvio Source Type: research

CO2 Hydrogenation to CH3OH on Metal-Doped TiO2(110): Mechanisms, Strain Effect and a New Thermodynamic-Kinetic Relation
Chemphyschem. 2024 Mar 24:e202300608. doi: 10.1002/cphc.202300608. Online ahead of print.ABSTRACTSurface strain and linear thermodynamic-kinetic relation are interesting topics in catalysis. Development of low temperature methanol catalysts of high activity and selectivity is of particularly importance for conversion of CO2 to methanol. In the present paper CO2 hydrogenation to methanol on Znx@TiO2(110) (x = 0-2) was explored using density functional calculations and microkinetic simulations. The reaction mechanisms on the three model systems were determined and it is shown that Zn2@TiO2(110) is the most active. The most f...
Source: Chemphyschem - March 24, 2024 Category: Chemistry Authors: Huili Lu Deshuai Yang Zhao-Xu Chen Source Type: research

Theoretical characterization of germanene doped with main group elements
Chemphyschem. 2024 Mar 24:e202400139. doi: 10.1002/cphc.202400139. Online ahead of print.ABSTRACTHerein, using density functional calculations, we studied the substitutional doping in germanene with B, C, N, O, Al, Si, P, S, Ga, As, and Se. Nitrogen is the element that can be more easily incorporated into the germanene lattice, followed by silicon, carbon, and boron. Almost all dopants were efficient in opening a band-gap. Yet, caution should be taken because this opening strongly depends on the dopant concentration. Carbon and sulfur were the most effective elements for band-gap opening. C-doping generates the lowest effe...
Source: Chemphyschem - March 24, 2024 Category: Chemistry Authors: Pablo Andres Denis Jose Laranjeira Julio Sambrano Source Type: research